Velocity-modulated electrondischarge device



Nov. 22, 1949 B. c. GARDNER 2,488,906

VELOCITY-MODULATED ELECTRON DISCHARGE DEVICE Filed 001;. 31, 1945 Patented Nov. 22, 1949 OFFICE VELOCITY-MODULATED ELECTRON-' DISCHARGE DEVICE Bernard (3. Gardner, Waltham, Mass, assignor to Raytheon Manufacturing Company, Newton,

Mass, a corporation of Delaware Application October 31, 1945, Serial No. 625,732

This invention relates to electron-discharge devices, and more particularly to electron-discharge devices of the velocity-modulated types known as Klystrons and reflex Klystrons.

In certain instances, the tuned circuits, generally, cavity resonators, with which tubes of this character are commonly associated are integral with the equipment in which they are employed, and when such tubes become inoperative, it is necessary, in replacing the same, most accurately to fit the new tubes to the resonators. This is ex tremely difficult of performance, especially when operating in the field.

Furthermore, the lack of a permanent connection between the tube and the cavity resonator gives rise to oxidation and other impairment of the junction therebetween which results in poor electrical continuity.

It is, therefore, an object of the present invention to provide an electron-discharge device of the Klystron or reflex Klystron type in which the tube is permanently associated with the cavity resonator so that replacement may be elTected merely by removing the spoiled tube from its socket and substituting a new one therefor.

It is a further object of the present invention to provide an electron-discharge device of the general character indicated which includes, as an integral part of the cavity resonator thereof, a heat-radiating and tube-protecting shell surrounding said tube.

These, and other objects of the present invention, which will become more apparent as the detailed description thereof progresses, are attained, briefly, in the following manner:

An evacuated, dielectric envelope is provided to enclose an electron gun, a pair of grids spaced from said gun, and a repeller electrode spaced from said grids. Said grids are sealed through the walls of the envelope and are connected, respectively, to the terminals of a tuned circuit. Said tuned circuit consists of a cavity resonator which is integrally formed at one end of a conducting shell, the other end of which is supported on a base member. The arrangement is such that the tube itself is suspended within the shell in spaced relationship to the base member.

In the accompanying specification there is described, and in the annexed drawing shown, an illustrative embodiment of the electron-discharge device of the present invention. It is, however, to be clearly understood that the present invention is not to be limited to the details herein shown and described for purposes of illustration only, inasmuch as changes therein may be made without 1 Claim. (Cl. 315-5) the exercise of'invention, and within the true spirit and scope of the claims hereto appended.

In. said drawing, the single figure is a partial side elevational, partial vertical sectional view of a velocity-modulated electron-discharge device made in accordance with the principles of the present invention.

Referring now more in detail to the aforesaid illustrative embodiment of the present invention, with particular reference to the drawing illustrating the same, the numeral Ill generally designates a velocity-modulated electron-discharge device of the type known as a reflex Klystron.

Said device comprises an evacuated glass envelope H having a reentrant press It formed at one end thereof from which there is supported an electron gun, said gun consisting, for example, of a suitably coated cathode l3, which is adapted to be heated by a filament M to a temperature of thermionic emission, surrounded by an accelerating electrode l5.

Spaced from said electron gun is a pair of grids l6 and I1, said grids being supported as by having portions l8 and I9 thereof sealed through the walls of the envelope II and provided, at their outer edges, respectively, with outwardly-directed flanges l8 and I9.

Spaced from said grids l6 and I1 is a repeller electrode 20 which may be supported, for example, at the end of a lead-in conductor 2| sealed through the envelope II at the end thereof oppo site the press l2.

Surrounding the tube thus far described is a conducting shell, made, preferably, of a nickelsteel alloy having approximately the same temperature coefficient of expansion as the glass envelope II, and consisting of a cylindrical heatradiating and tube-housing portion 22 and an integrally formed toroidal cavity resonator 23. The cavity resonator 23 has its edges soldered or otherwise permanently secured, respectively, to the flanges I 8 and I9 of the external portions l8 and [9 of the grids l6 and I1, and the housing portion 22 is crimped at its lower end, as at 24, to a base member 25, the arrangement being such that the tube portion of the device is supported in spaced relationship to said base member.

The cavity resonator 23 is provided with one or more threaded, tubular extensions 26 receptive of adjustable plugs 21 carrying, at their inner ends, tuning members 28, said tuning members extending into said cavity resonator to tune the same in a manner well known to those skilled in the art.

The cavity resonator is also provided with a tubular extension 29 which, together with a coupling loop 30, may be connected to a transmission line to convey power from the device.

This completes the description of the aforesaid illustrative embodiment of the electron-discharge device of the present invention. It will be noted that said device incorporates, as a permanent part thereof, a tuned circuit in the form of a. cavi y resonator, and thereby eliminates the disadvantages of the prior art referred to in earlier portions of this specification. It will be further noted that said device includes a heat-radiating and tube-protecting shell which renders the same more rugged than devices of the prior art.

Other objects and advantages of the present invention will readily occur to those skilled in the art to which the same relates.

What is claimed is:

An electron-discharge device comprising: a dielectric envelope; a plurality of electrodes including an electron gun, a pair of grids, and a repeller electrode enclosed in said envelope; said grids having annular flanges formed therewith and sealed through the walls of said envelope; a base member for mounting said device in a socket; said BERNARD C, GARDNER.

REFERENCES CITED The following references are of record in the file of this patent:

- UNITED STATES PATENTS Number Name Date 2,280,980 Samuel Apr. 28, 1942 2,353,742 McArthur July 18, 1944 2,395,043 Goodchild Feb. 19, 1946 2,400,753 Haefi May 21, 1946 2,404,261 Whinnery Feb. 16, 1946 2,406,850 Pierce Sept. 3, 1946 Turner Sept. 24, 1946 

